An apparatus for applying energy to an object is, for example, used in the field of interventional treatment of atrial fibrillation, wherein cardiac tissue is denaturized by thermal therapy. Radio Frequency energy is applied to the cardiac tissue using a catheter and thermal energy is generated due to resistive losses in the tissue of the myocardium. The heated muscle cells in the cardiac tissue die off and lose their biological function, which can be measured by an increase in the tissue impedance.
U.S. Pat. No. 5,830,209 discloses a laser catheter comprising multiple optical fibers for applying optical energy to the tissue of a heart. The optical fibers are arranged in a small circle at the distal end of the catheter and emit light substantially in the same direction such that they form a broad light spot on the surface of the tissue when the catheter is in contact with the tissue. In order to apply energy along a line on the tissue, the catheter has to be moved along the line, i.e. the optical energy has to be applied at different locations along the line, wherein between the different locations the catheter has to be detached from the tissue, moved to a next location and again attached to the tissue.
This leads to an inaccurate application of optical energy to the tissue, in particular, if the object is moving.